Registration Dossier

Administrative data

Endpoint:
phototransformation in water
Type of information:
other: Technical discussion
Adequacy of study:
key study
Study period:
Not applicable
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The reliability rating was 2 because the information presents a technical summary tather than the results of a specific study.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1977
Report Date:
1976

Materials and methods

Test guideline
Qualifier:
no guideline followed
Guideline:
other: Technical discussion
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Radiolabelling:
no

Results and discussion

Transformation products:
not measured

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test substance does not absorb light within a range of 290 to 750 nm. Therefore, direct photolysis will not contribute to the degradation of the test substance in the aquatic environment because it does not absorb light at wavelengths >290 nm, i.e., in the range that contribute to this process.
Executive summary:

Direct photochemical degradation in water occurs through the absorbance of solar radiation by a chemical substance. If the absorbed energy is high enough, then, in the resultant excited state, the chemical may undergo a transformation. A prerequisite for direct photodegradation is the ability of one or more bonds within a molecule to absorb ultraviolet (UV)/visible light in the 290 to 750 nm range. Light wavelengths longer than 750 nm do not contain sufficient energy to break chemical bonds, and wavelengths below 290 nm are shielded from the earth by the stratospheric ozone layer. An approach to assessing the potential for the test substance to undergo direct photochemical degradation is to assume that degradation will occur in proportion to the amount of light wavelengths >290 nm absorbed by substance molecules.  The test substance does not absorb light within a range of 290 to 750 nm. Therefore, direct photolysis will not contribute to the degradation of the test substance in the aquatic environment because it does not absorb light at wavelengths >290 nm, i.e., in the range that contribute to this process.